The present invention relates to banjos and similar stringed instruments, and particularly to an apparatus for attaching the neck of such a stringed instrument to the body thereof.
Stringed musical instruments, such as banjos, guitars, and the like, comprise a body portion and an elongated neck which extends away from the body portion. A plurality of strings are attached to a tailpiece fastened to the body, the strings extending over a bridge, across the body, and along the neck. Ordinarily the neck is securely and permanently attached to the body of such an instrument during manufacture, and the relationship between the position of the strings and the surfaces of the neck and body of the instrument is variable only insofar as the height and location of a bridge resting on the top of the body portion of the instrument may be adjusted.
Particularly in the case of banjos, the body construction has a great deal of influence on the characteristic sound produced by the instrument. Because of the relatively high cost of well built banjos, it is sometimes desirable to provide for detachability of the neck from the body of such a banjo so that one neck may be used, for example, on an acoustical banjo body, as well as on a body equipped with electromagnetic pickups providing for amplification of the sound produced by the strings.
Adjustment of the neck with respect to the body of a stringed musical instrument may require adjustment of the height, vertical angle, lateral angle, and rotational position of the neck relative to the body of such an instrument.
Previously, in mounting a neck to the body of an instrument, it has commonly been the practice to adjust the position and angular orientation of the neck with respect to the body by the use of shims interposed as required between the base of the neck and the body at the point of attachment. While it is possible to provide acceptable results in this manner, the process of adjustment is tedious.
Adjustment of the angle between the top of the body and the top of the neck in a plane extending through the neck and the body, hereinafter referred to as a vertical plane, alters the height of the strings above the frets or fingerboard surface of the neck. Such adjustment is required because too great a height of the strings above the frets makes it impossible to stop the strings easily and efficiently on the frets, while too small a height of the strings above the frets can permit undesirable interference of the frets with the normal vibration of the string, causing an undesirable and annoying buzzing sound as the instrument is played.
Lateral adjustment of the neck with respect to the body, that is, adjustment of the angle in a plane parallel the neck and the top of the body, hereinafter referred to as a horizontal plane, affects the location of the outermost strings of the instrument relative to a respective edge of the neck. Lateral angle misalignment may result in a string extending alongside the neck, rather than above the fingerboard or fretboard, so that it is impossible to stop the string. Such misalignment also results in application of unbalanced lateral forces to the neck, which forces may eventually cause the neck to warp.
Rotational misalignment of the neck with respect to the body, about a longitudinal axis of the neck, may result in the strings on one side of the neck being further above the fingerboard or fretboard than strings on the other side, with the result that the instrument will be awkward to play. Particularly in the case of an electrically amplified instrument, such misalignment of the neck with respect to the body may also result in unequal spacing between the strings and the sensors intended to pick up the vibration of the individual strings for electrical amplification. This, of course, can result in different sound volume being produced by the different strings, or a requirement to make difficult adjustments to the amplifier.
Finally, the overall length of the instrument from the bridge to the nut at the head end of the neck must bear the proper physical relationship to the spacing between the frets of a fretboard, and in an instrument such as an electrically amplified guitar or banjo having a fixed bridge, inaccuracy of this length results in inaccuracy of at least some of the tones produced by the instrument.
Previous devices have attempted to deal with at least some of these problems, but without complete success. For example, Oleson U.S. Pat. Nos. 536,649, DeWick 1,567,359, Lange 1,611,648, Strube 1,671,942, Larson 1,818,631, and Bardsley 1,206,650 all provide for adjustment of the neck of a stringed musical instrument with respect to the body, about either one or two axes of rotation. While this may be acceptable in the case of conventional acoustical banjos, in which the bridge is movable, the result of misalignment with respect to the body is unacceptable in an instrument in which the position of the bridge is fixed.
What is needed, then, is an improved way of connecting the neck to the body of a stringed musical instrument such as an electric banjo, providing for adjustment of vertical location, vertical angle, lateral angle, and rotational position of the neck with respect to the body of the instrument in order to produce the accurate tones throughout the instrument's range.